I'm not about to look up all what is included in the kit (I'm just too lazy) but will say this. Poly makes great stuff. I have a bunch of their stuff on my rig. However, I also believe RockKrawler stuff is hard to beat price wise.
For instance, I am running RK control arms, tie rod, and track bars, but Poly track bar brackets, hi-steer drag link and springs. I'm running normal Bilstein 5100s. And just for kicks, I have Teraflex bumpstop extensions and stabilizer. lol
Polys stuff is nice because it's bolt on instead of many of RKs things being weld on. The adjustments are easier on the Poly stuff too because of their design. However, once it's adjusted correctly, you never have to touch it again so not that big of a deal. RK stuff is also all solid bar instead of tube and all I can say is they are tough. Not to mention RKs warranty. I'm not sure of Polys warranty.
Lastly, for me I like the joints on the RK arms better. I've just seen too many of the johnny joint type joints wear out in the Michigan weather here. RKs design seems more durable over the long haul, and they are based in New York so I figure they designed their stuff to last in the type of weather that they see. So far, my joints are still like new.
Support the sport. GLFWDA.org